This invention relates to a push-pull amplifier employed in audio equipments as an output amplifier.
Push-pull amplifiers are referred to generally as power amplifiers, and various types of such power amplifiers have been conventionally employed. Basic types of the power amplifiers are classes "A" and "B" complementary push-pull amplifiers. The class "A" complementary push-pull amplifier is advantageous in that no switching distortion is produced, since a pair of output transistors always operates in the active region and it does not shift to the cut-off region. This type is disadvantageous in that heat loss is large due to a large amount of bias current. On the other hand, in the class "B" complementary push-pull amplifier heat loss is small since the amount of bias current is relatively small in comparison with a class "A" amplifier. However, switching distortion is inversely produced due to the fact that the pair of output transistors alternatively shifts to the cut-off region.